fix: 修复 tag/changelog 生成范围，增加 --auto 模式

- fix(get_tags): 使用 find_object+peel_to_commit 支持 annotated tag
- fix(changelog): insert_changelog_entry 替换覆盖逻辑，保留已有章节
- feat: parse_changelog_versions 按 semver 降序提取版本
- feat: sort_tags_by_semver 取代纯时间排序
- feat(tag --auto): 优先读 Cargo.toml/pyproject.toml，回退 commit 分析
- feat(changelog): 无 --from 时自动检测 changelog 最高已有版本
- refactor: TagInfo::version_name(), GitRepo::find_tag_by_version()

src/git/tag.rs

@@ -1,6 +1,7 @@
 use super::GitRepo;
 use anyhow::{Result, bail};
 use semver::Version;
+use std::path::Path;
 
 /// Tag builder for creating tags
 pub struct TagBuilder {
@@ -327,3 +328,193 @@ pub fn list_tags(
         Ok(filtered)
     }
 }
+
+/// Sort tags by semver version descending, then by time descending.
+/// Non-semver tags are placed after semver tags, sorted by time descending.
+pub fn sort_tags_by_semver(tags: &mut [super::TagInfo]) {
+    use semver::Version;
+
+    tags.sort_by(|a, b| {
+        match (
+            Version::parse(a.version_name()),
+            Version::parse(b.version_name()),
+        ) {
+            (Ok(va), Ok(vb)) => {
+                // Both semver: version descending, then time descending as tiebreaker
+                vb.cmp(&va).then_with(|| b.time.cmp(&a.time))
+            }
+            (Ok(_), Err(_)) => std::cmp::Ordering::Less,   // semver tags first
+            (Err(_), Ok(_)) => std::cmp::Ordering::Greater, // semver tags first
+            (Err(_), Err(_)) => b.time.cmp(&a.time),        // both non-semver: time descending
+        }
+    });
+}
+
+/// Read the project version from Cargo.toml or pyproject.toml.
+/// Returns None if no project config file is found or version cannot be read.
+pub fn read_project_version(project_dir: &Path) -> Option<Version> {
+    // Try Cargo.toml first
+    let cargo_path = project_dir.join("Cargo.toml");
+    if cargo_path.exists() {
+        if let Ok(content) = std::fs::read_to_string(&cargo_path) {
+            if let Ok(value) = content.parse::<toml::Value>() {
+                if let Some(version) = value
+                    .get("package")
+                    .and_then(|p| p.get("version"))
+                    .and_then(|v| v.as_str())
+                {
+                    if let Ok(ver) = Version::parse(version) {
+                        return Some(ver);
+                    }
+                }
+            }
+        }
+    }
+
+    // Try pyproject.toml
+    let pyproject_path = project_dir.join("pyproject.toml");
+    if pyproject_path.exists() {
+        if let Ok(content) = std::fs::read_to_string(&pyproject_path) {
+            if let Ok(value) = content.parse::<toml::Value>() {
+                if let Some(version) = value
+                    .get("project")
+                    .and_then(|p| p.get("version"))
+                    .and_then(|v| v.as_str())
+                {
+                    if let Ok(ver) = Version::parse(version) {
+                        return Some(ver);
+                    }
+                }
+            }
+        }
+    }
+
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::git::TagInfo;
+
+    fn make_tag(name: &str, time: i64) -> TagInfo {
+        TagInfo {
+            name: name.to_string(),
+            target: "abc123".to_string(),
+            message: String::new(),
+            time,
+        }
+    }
+
+    #[test]
+    fn test_sort_by_semver_descending() {
+        let mut tags = vec![
+            make_tag("v1.0.0", 100),
+            make_tag("v2.0.0", 200),
+            make_tag("v1.5.0", 150),
+        ];
+        sort_tags_by_semver(&mut tags);
+        let names: Vec<&str> = tags.iter().map(|t| t.name.as_str()).collect();
+        assert_eq!(names, vec!["v2.0.0", "v1.5.0", "v1.0.0"]);
+    }
+
+    #[test]
+    fn test_sort_semver_ties_broken_by_time() {
+        let mut tags = vec![
+            make_tag("v1.0.0", 100),
+            make_tag("v1.0.0", 300),
+            make_tag("v1.0.0", 200),
+        ];
+        sort_tags_by_semver(&mut tags);
+        let times: Vec<i64> = tags.iter().map(|t| t.time).collect();
+        assert_eq!(times, vec![300, 200, 100]);
+    }
+
+    #[test]
+    fn test_sort_non_semver_tags_at_end() {
+        let mut tags = vec![
+            make_tag("release-2024", 400),
+            make_tag("v1.0.0", 100),
+            make_tag("staging", 300),
+            make_tag("v0.2.0", 200),
+        ];
+        sort_tags_by_semver(&mut tags);
+        let names: Vec<&str> = tags.iter().map(|t| t.name.as_str()).collect();
+        assert_eq!(names[0], "v1.0.0");
+        assert_eq!(names[1], "v0.2.0");
+        assert_eq!(names[2], "release-2024");
+        assert_eq!(names[3], "staging");
+    }
+
+    #[test]
+    fn test_sort_no_prefix_semver() {
+        let mut tags = vec![
+            make_tag("1.0.0", 100),
+            make_tag("2.0.0", 200),
+            make_tag("0.1.0", 50),
+        ];
+        sort_tags_by_semver(&mut tags);
+        let names: Vec<&str> = tags.iter().map(|t| t.name.as_str()).collect();
+        assert_eq!(names, vec!["2.0.0", "1.0.0", "0.1.0"]);
+    }
+
+    #[test]
+    fn test_sort_all_non_semver_by_time() {
+        let mut tags = vec![
+            make_tag("release-2024", 100),
+            make_tag("release-2023", 300),
+            make_tag("beta", 200),
+        ];
+        sort_tags_by_semver(&mut tags);
+        let times: Vec<i64> = tags.iter().map(|t| t.time).collect();
+        assert_eq!(times, vec![300, 200, 100]);
+    }
+
+    #[test]
+    fn test_read_project_version_from_cargo_toml() {
+        let dir = tempfile::TempDir::new().unwrap();
+        std::fs::write(
+            dir.path().join("Cargo.toml"),
+            "[package]\nname = \"test\"\nversion = \"0.3.0\"\n",
+        )
+        .unwrap();
+        let version = read_project_version(dir.path());
+        assert_eq!(version, Some(Version::new(0, 3, 0)));
+    }
+
+    #[test]
+    fn test_read_project_version_from_pyproject_toml() {
+        let dir = tempfile::TempDir::new().unwrap();
+        std::fs::write(
+            dir.path().join("pyproject.toml"),
+            "[project]\nname = \"test\"\nversion = \"0.2.1\"\n",
+        )
+        .unwrap();
+        let version = read_project_version(dir.path());
+        assert_eq!(version, Some(Version::new(0, 2, 1)));
+    }
+
+    #[test]
+    fn test_read_project_version_no_config_files() {
+        let dir = tempfile::TempDir::new().unwrap();
+        let version = read_project_version(dir.path());
+        assert_eq!(version, None);
+    }
+
+    #[test]
+    fn test_read_project_version_cargo_takes_priority() {
+        let dir = tempfile::TempDir::new().unwrap();
+        std::fs::write(
+            dir.path().join("Cargo.toml"),
+            "[package]\nname = \"test\"\nversion = \"0.3.0\"\n",
+        )
+        .unwrap();
+        std::fs::write(
+            dir.path().join("pyproject.toml"),
+            "[project]\nname = \"test\"\nversion = \"0.2.1\"\n",
+        )
+        .unwrap();
+        let version = read_project_version(dir.path());
+        assert_eq!(version, Some(Version::new(0, 3, 0)));
+    }
+}